Propshaft damper and method of assembly

ABSTRACT

A propshaft damper for a vehicle is provided. The propshaft damper includes an inertia ring where the inertia ring having an inner ring. A rubber track is positioned on inner ring, the rubber track having an first inner surface. A transmission flange is further provided having a second inner surface and connected to the inertia ring. A hub is provided connecting the inertia ring to the flange. The hub having a first section and a second section where the first section of the hub includes a first outer surface and the second section includes a second outer surface. The first inner surface of the hub connected to the first outer surface of the hub. Further, the second outer surface of the hub is connected to the second inner surface of the flange thereby connecting inertia track and the flange by means of the hub in a secure press-fit connection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a Continuation of application Ser. No. 14/105,348filed on Dec. 13, 2013. Application Ser. No. 14/105,348 claims thebenefit of U.S. Provisional Application 61/776,945 filed on Mar. 12,2013. Application Ser. No. 14/105,348 claims the benefit of U.S.Provisional Application 61/736,771 filed on Dec. 13, 2012, the contentsof which are incorporated herein in their entirety.

FIELD OF THE INVENTION

This invention relates generally to dampers for vehicle suspensionsystems. More particularly, this invention relates to a propshaft damperto minimize vibration in a vehicle suspension system.

BACKGROUND OF THE INVENTION

Noise is a common customer complaint within the interior compartment ofa vehicle. The firings of cylinders in an internal combustion engine ofa vehicle may generate torsional vibrations thus causing noise heard bythe user of the vehicle. These periodic firings generate torsionalvibrations as a fixed order of the engine rpm. An excitation sweepstarting at idle up to the maximum engine speed is measured andgraphically depicted. Various multiple degrees of freedom have severaleigenforms per its inertia, torsional rates, and dampening. Eacheigenform has a certain frequency, vibration shape, and resonantapplication. Systems not having dampers on the propshaft exhibit higherfrequency versus amplification on a system with amplifying eigenmode(resonance) not having dampers on the propshaft.

The noise and vibration of an amplified eigenmode in resonance heard bythe user of the vehicle is significantly reduced through the use oftorsional propshaft dampers. The propshaft damper works as an addedsingle degree of freedom system tuned to the problem eigenform of thedriveline. FIG. 2 illustrates the graph 30 showing frequency versusamplification of the reduction of torsional resonant vibration whenusing a damper at line 34 and not having a damper at line 32. Line 34 isan example of the frequency versus amplification of the presentinvention.

Several known propshaft dampers exist such as a damper having rotatingsupport pins and being pressed onto a flange/shaft OD. Other dampersincludes a damper having a track but assembled with a rubber couplingand being pressed to an OD of a flange protrusion which accommodates acenter sleeve. Other dampers include a damper having a rubber couplingor a propshaft damper pressed to a minimum shaft flange accommodatedinto a cv-joint. Even further, these dampers all require the user of abolt or other fastener for assembly. The dampers of the prior art arefrequently prohibitively expensive to manufacture when assembled betweena u/cv-joint and a transmission flange because of the number ofcomponents required, the weight and assembly costs. As such, thereexists a need in the art to provide a propshaft damper producingeffective results at a lower cost.

SUMMARY OF THE INVENTION

The present invention provides for a propshaft damper for a vehicle. Thepropshaft damper includes an inertia ring where the inertia ring havingan inner ring. A rubber track is positioned on inner ring, the rubbertrack having an first inner surface. A transmission flange is furtherprovided having a second inner surface and connected to the inertiaring. A hub is provided connecting the inertia ring to the flange. Thehub having a first section and a second section, the first section ofthe hub having a first outer surface and the second section having asecond outer surface. The first inner surface of the hub connected tothe first outer surface of the hub. Further, the second outer surface ofthe hub is connected to the second inner surface of the flange therebyconnecting inertia track and the flange by means of the hub in a securepress-fit connection, or a fastener. The present invention offers thepossibility to assemble a damper between two flanges without using adeep drawn stamping or a following assembly of inertia ring withsubassembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a vehicle having a propshaft and propshaft damperpositioning;

FIG. 2 is a graphical representation of frequency versus amplificationof a vehicle with and without propshaft dampening at resonantamplification;

FIG. 3 is a partial cross-sectional view and partial perspective view ofthe first embodiment of the damper of the present invention;

FIG. 4 is a partial cross-sectional perspective exploded view of thefirst embodiment of the damper of the present invention;

FIG. 5 is a side view of the first embodiment of the damper of thepresent invention;

FIG. 6 is a partially exploded perspective view of the first embodimentof the damper of the present invention;

FIG. 7 is a partially exploded, partial cross-sectional perspective viewof a second embodiment of the damper of the present invention;

FIG. 8 is a side view of the second embodiment of the damper of thepresent invention;

FIG. 9 is a cross-sectional side view of a third embodiment of thedamper of the present invention;

FIG. 10 is a cross-sectional perspective view of the third embodiment ofthe damper of the present invention;

FIG. 11 is a cross-sectional view of a fourth embodiment of the damperof the present embodiment; and

FIG. 12 is an alternative cross-sectional view of the fourth embodimentof the damper of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides for an improved propshaft damper having acentered rubber track. The centered rubber track provides sufficientradial damper rate for balancing and a cost savings through the reducednumber of components (i.e., no friction bearings or support pins),improved durability through less rubber strain, and a robust designwithout dirt contamination or wear. The propshaft damper includes aninertia ring where the inertia ring having an inner ring. The rubbertrack is positioned on inner ring, the rubber track having an firstinner surface.

A transmission flange is further provided having a second inner surfaceand connected to the inertia ring. A hub is provided connecting theinertia ring to the flange. The hub having a first section and a secondsection, the first section of the hub having a first outer surface andthe second section having a second outer surface. The first innersurface of the hub connected to the first outer surface of the hub.Further, the second outer surface of the hub is connected to the secondinner surface of the flange thereby connecting inertia track and theflange by means of the hub in a secure press-fit connection.

Previously known damper assemblies having a centered rubber trackinclude a press fit hub to the minimum diameter of shaft flange, a pressfit to protrusion of the multi arm flange, or bolted between atransmission and CV/U-joint flange. The present invention offers thepossibility to assemble a damper between two flanges without using adeep drawn stamping or a following assembly of inertia ring withsubassembly.

The flange of the present invention requires an inner diameter having apress fit tolerance. The flange further must include areas of protrusionor recession so that the inertia ring with apertures can move in thesame plane without contacting the flange.

FIGS. 3-6 illustrate the components of the propshaft damper 100 of thepresent invention. The damper 100 includes an inertia ring 102, a damperhub 106 and a centered rubber track 108. The inertia ring 102 isconnected to the damper hub 106 through molding/vulcanization of therubber in the rubber track 108. The rubber of the rubber track is moldeddirectly (i.e. integrated) to the metal of inertia ring 102 (i.e.vulcanization). The rubber track 108 is centered (i.e. close to therotating axis) as close as possible to provide sufficient radialstiffness. The centered nature of the track 108 will ensure optimizedbalance properties with the need for support pins. The rubber track 108negates the need for fasteners or other support pins.

The hub 106 is further provided in the center of the inertia ring 102.The rubber of the rubber track 108 is defined as rubber, polymers,plastics, polymer-like or plastic-like materials. The hub 106 may be acut and machined steel, other metal, plastic, plastic-like, polymer orpolymer-like tube. The present invention provides for a single mountingplane through a plurality of transmission flange protrusions and anoptimized alignment through press fit area in the machined tube.Alternatively, the protrusions may be provided on the shaft flange. Thetransmission flange or a shaft flange includes a plurality protrusionswhich extend through the apertures of the inertia ring connecting to theother of the transmission flange or the shaft flange.

The inertia ring 102 is a casting (without a subassembly) having lowtooling cost. The inertia ring 102 further includes an inner ring 175,or generally circular inner portion positioned close to the drive shaft.In the present embodiment, the inertia ring is made of a cast iron.Other metals or sinter metals may be used to produce the inertia ring.The inertia ring includes a plurality of apertures 120 a, 120 b. Theapertures, or travel limiters, 120 a, 120 b may further include a rubberor plastic coating to operate as a travel limiter without generating anyfurther noise. The apertures 120 a, 120 b may be include a separaterubber snubber to form the snubber surface attached as a separatecomponent. This rubber coating or snubber reduces noise and preservesthe inertia ring in the event of a collision.

The coatings 122 are provided on an inner surface of the apertures 120a, 120 b. The coatings (or surfaces) 122 are molded directly (i.e.integrated) to the inertia ring 102. This molding/vulcanization processof molding the coatings 122 may take place at the same time as therubber track 108 is molded to the inertia ring 102 to save time andmoney in the manufacturing process. Integrated sealing lips 140, asshown in FIG. 3, are further provided to increase protection againstdirt and excessive heat. The sealing lips 140 may also be molded at thesame time as the molding of the rubber track 108 and the coatings 122.

The flange 104 includes a plurality of protrusions 124. In the presentembodiment, the protrusions 124 are generally cylindrical having anouter circumference 125 and an upper surface 127. In furtherembodiments, the protrusions will vary in size and dimension (as in theflanges of FIGS. 19-22) and are not limited to a cylindricalconfiguration. The protrusions 124 are adapted to engage with theapertures 120 located on the inertia ring 102. The protrusions 124extend through the apertures 120 a, 120 b, etc. allowing the inertiaring to move relative to the flange to move together on the same planewithout the flange 104 contacting the inertia ring 102. The inertia ringand hub 106 are press fit into the flange 104.

A plurality of spokes 170 are positioned between the apertures 120 a,120 b. These spokes are defined as the space between the apertures 120a, 120 b extending between the inner ring and the outer ring. In thepresent embodiments as shown in FIG. 4, the spokes 170 are wide. Inother embodiments (such as shown in FIG. 8), the spokes are more narrowand appear more like traditional spokes.

FIG. 6 illustrates the relation of the u-joint 130 (of the propshaft) tothe damper 100. An aperture 132 located on a shaft flange 134 of thepropshaft connects to the protrusion 124 of the flange 104. Theprotrusion 124 of the flange 104 includes an aperture 128 extendingthrough the protrusion 124. A bolt then extends through the aperture 132through the aperture 128 of the flange 104 and thus accordingly throughthe aperture 120 of the inertia ring thereby aligning the propshaft withthe transmission flange 104 and allowing the inertia ring to rotate onthe same plane as the flange 104 and protrusions 124.

FIGS. 4 and 6 illustrates the damper 100 in relation to the u-joint 130.The inertia ring further includes dirt detracting chamfers 140 locatedon an outer edge of the inertia ring 102. The outer surface 175 of theinertia ring 102 acts as a temperature shield to prevent hightemperatures from the closely located exhaust from damaging the rubbertrack 108. The flange 104 and the u-joint (flange) 130 also act astemperature shields for the rubber track 108. FIG. 14 illustrates acentered rubber track 108 located on the inertia ring 102.

FIG. 3 illustrates yet another improvement of the present invention. Atorque flow 125 is shown through the flange 104 and the u-joint (andflange of the u-joint 130). The torque is not transmitted to the damper100. This permits the damper 100 to be made of lighter material andallows the damper to serve only its primary purpose of dampening.

The hub 106 illustrates a 3-section configuration. The hub 106 furtherincludes sections 106A, 106B and 106C. The sections 106A, 106B and 106Cinclude varying outer diameters allowing for easier and/or more secureconnections between the flanges. By way of example, the OD of section106A is configured to press-fit with the flange 104. The change in theOD over the varying sections provides for alignment of the flange 104and the flange of the u-joint 130. Section 106B provides for an OD forthe rubber track 108. Section 106C provides for an intermediate fit forfurther aligning the hub 106 with the u-joint 103 (or shaft flange 134of the u-joint 130). The third section 106C accommodates an innersurface of a shaft flange to align the shaft flange 134.

These arrangements allow for accurate alignment of the damper 100 withthe flange 104 (and the flange of the u-joint 130). The hub 106 mayinclude more or less sections (i.e. 2, 3, 4, 5 . . . etc.) according tothe need for alignment and based on customer need.

FIGS. 3 and 6 illustrate the u-joint 130 connected to the flange 104.The inertia ring 102 further includes sealing lips 140 providing forcomplete encapsulation against dirt and heat through the vulcanizedsealing lips 140. The integrated sealing lips 140 prevent dirt and heatfrom entering the system.

The flange 104 further includes protrusions 124 extending through theaperture of the inertia ring 102. The flange connects to the inertiaring by means of a press fit configuration. Specifically, the hub 106further includes a first outer surface 171 and a second outer surface172. The first outer surface 171 connects to an outer surface 174 of therubber track 108 of the inertia ring 102. Further, the second outersurface 172 of the hub 106 connects to an inner surface 176 of theflange 104. These connections are made in a press-fit arrangement tocreate a secure connection. Alternatively, the hub, flange and inertiaring are bond molded together, optionally molded together at the sametime as the rubber coating on the apertures.

FIGS. 7-8 illustrate a second embodiment of the present invention. Adamper assembly 200 discloses the damper concept between a cv-joint 280and transmission flange 204. The inertia ring 202 is connected throughthe rubber track 208 with the damper hub 206. The rubber track 208,similar to rubber track 108 of the first embodiment, may also have anL-shaped configuration. The inertia ring 202 further includes an innerring 275, or generally circular inner portion positioned close to thedrive shaft. The damper hub 206 is connected to the transmission flange204 with a press fit configuration. The damper hub, in the presentembodiment, includes a 2-section configuration including section 206Aand section 206B. This 2-section configuration provides for simplifiedand accurate alignment. The OD of section 206B provides a press-fitconnection to the transmission flange 204 to securely connected to aninner surface (and inner diameter) 262 of the transmission flange 204. Asecondary flange alignment between the transmission flange 204 at 264and the cv-joint at point 282. Integrated sealing lips 260 are adaptedto prevent dirt contamination.

Rubber coated spokes 270 are provided on the inertia ring 202 to preventnoise when travel limiting. The apertures 220 of the inertia ring 202are larger in size to accommodate the protrusions 224 of thetransmission flange 204.

The flange 204 further includes protrusions 224 extending through theaperture of the inertia ring 202. The flange connects to the inertiaring by means of a press fit configuration. Specifically, the hub 206further includes a first outer surface 270 and a second outer surface272. The first outer surface 270 connects to an outer surface 274 of therubber track 208 of the inertia ring 202. Further, the second outersurface 272 of the hub 206 connects to an inner surface 276 of theflange 204. These connections are made in a press-fit arrangement tocreate a secure connection.

In a third embodiment as shown in FIGS. 9-10, the damper hub includes apress fit configuration and a mounting surface for a shaft nut. Damperassembly 300 discloses the damper concept between a cv-joint 390 andtransmission flange 304. The transmission flange 304 includes a hatchedinner surface 362 providing for a secure connection with a bolt or otherfastener.

The inertia ring 302 is connected through the rubber track 308 with thedamper hub 306. The inertia ring 302 further includes an inner ring 375,or generally circular inner portion positioned close to the drive shaft.The rubber track 308, similar to rubber track 108 of the firstembodiment, may also have an L-shaped configuration. The damper hub 306is connected to the transmission flange 304 with a press fitconfiguration (press fit for pre-assembly). The OD of section 306 aprovides a press-fit connection to the transmission flange 304. Thisconnection is shown in highlighted section A The OD of the section 306 bconnects to the rubber track 308 of the inertia ring 302. A plurality ofbolts 392 are provided connecting the joint 390 to the transmissionflange 304.

A mounting surface 310 for a shaft nut (not shown) is provided on thedamper hub 306. The mounting surface is generally perpendicular to aninner surface 312 of the damper hub 306. The mounting surface 310extends away from the inner surface 312 of the damper hub 306 into acenter portion of the damper hub 306. The mounting surface 310 isprovided to allow a nut or bolt head to rest thereon when extendingthrough the damper assembly 300.

The flange further includes protrusions 324 extending through theaperture of the inertia ring 302. The flange connects to the inertiaring by means of a press fit configuration. Specifically, the hub 306further includes a first outer surface 370 and a second outer surface372. The first outer surface 370 connects to an outer surface 374 of therubber track 308 of the inertia ring 302. Further, the second outersurface 372 of the hub 306 connects to an inner surface 376 of theflange 304. These connections are made in a press-fit arrangement tocreate a secure connection.

In a fourth alternative embodiment as shown in FIGS. 11-12, the damperhub includes a bolted hub configuration and a mounting surface for ashaft nut. Damper assembly 400 discloses the damper concept between acv-joint and transmission flange 404. The inertia ring 402 is connectedthrough the rubber track 408 with the damper hub 406. The inertia ring402 further includes an inner ring 475, or generally circular innerportion positioned close to the drive shaft. The rubber track 408,similar to rubber track of the first embodiment, may also have anL-shaped configuration.

The damper hub 406 includes a first surface 406 a and a second surface406 b. Further, the inertia ring 402 includes a first surface 402 a anda second surface 402 b. In the present embodiment, the first surface 406a of the hub 406 is generally in line and parallel with the firstsurface 402 a of the inertia ring. Correspondingly, the second surface406 b of the hub 406 is generally in line and parallel with the secondsurface 402 b of the inertia ring. Various other embodiments illustratethe second surface 406 b extending past the second surface 402 b of theinertia ring 402, and then press fit into a flange. The hub 406 of thepresent embodiment is not press fit into the flange 404. Rather, the hub406 will be bolted to the flange 404 by means of a bolt 466 (andcorresponding drive shaft structure 464, 468) and nut 490.

The hub further includes a first outer surface 470 and a second outersurface 472. The first outer surface 470 connects to an outer surface474 of the rubber track 408 of the inertia ring 402. Further, the secondouter surface 472 of the hub 406 connects to an inner surface 476 of theflange 404.

A mounting surface 410 for a shaft nut and bolt 490 is provided on thedamper hub 406. The mounting surface is generally perpendicular to aninner surface 412 of the damper hub 406. The mounting surface 410extends away from the inner surface 412 of the damper hub 406 into acenter portion of the damper hub 406. The mounting surface 410 isprovided to allow a nut or bolt head to rest thereon when extendingthrough the damper assembly 400.

Rubber coated spokes 470 are provided on the inertia ring 402 to preventnoise when travel limiting. The apertures 420 of the inertia ring 402are larger in size to accommodate the protrusions 424 of thetransmission flange 404. The present invention further includes a methodof assembly of the above embodiments of the damper assembly. The methodof assembling propshaft damper having a hub, an inertia ring and atransmission flange is provided including the steps of applying a rubbertrack to an inner ring of the inertia ring, the rubber track having aninner surface. The rubber may be applied as a separate piece or moldedto the metal. The method further includes the step of applying a rubbersurface to a plurality of apertures on the inertia ring, the rubber ofthe apertures applied at the same time the rubber track is applied tothe inner ring of the inertia ring. Again, the rubber may be applied asa coat (such as molded to the metal) or attached as a separatecomponent. The method then includes the steps of connecting a firstsection of the hub to the inner surface of the rubber track in apress-fit configuration and connecting a second section of the hub to aninner surface of a transmission flange in a press fit configuration.Alternatively, the hub, the transmission flange and the inertia ring maybe molded together. This alternate method requires molding a firstsection of the hub to the inner surface of the rubber track and moldinga second section of the hub to an inner surface of the transmissionflange. All of the components above may be connected via mold bonding ora press-fit configuration.

The invention is not restricted to the illustrative examples andembodiments described above. The embodiments are not intended aslimitations on the scope of the invention. Methods, apparatus,compositions, and the like described herein are exemplary and notintended as limitations on the scope of the invention. Changes thereinand other uses will occur to those skilled in the art. The scope of theinvention is defined by the scope of the appended claims.

1. A propshaft damper for a vehicle, the propshaft damper comprising: aninertia ring, the inertia ring having an outer ring and an inner ring,the inner ring having an inner diameter, the inertia ring having aplurality of apertures, the apertures separated by a plurality ofspokes; a rubber track positioned on the inner diameter of the innerring of the inertia ring, the rubber track having an inner surface, therubber track is located spaced apart from but close to a rotating axisof the damper to provide a high radial stiffness; a damper hub having afirst section and a second section, the first section of the hub havingan outer surface, the second section having an outer surface, the innersurface of the rubber track accommodating the first section of the hub,the second section of the hub connected with an inner surface of aflange by means of the hub.
 2. The propshaft damper of claim 1 where theflange is a transmission flange.
 3. The propshaft damper of claim 1where the flange is a shaft flange.
 4. The propshaft damper of claim 1wherein the inner surface of the rubber track has a press-fit toleranceto securely connect the rubber track to the outer surface of the firstsection of the hub.
 5. The propshaft damper of claim 1 wherein the outersurface of the rubber track has a press-fit tolerance to securelyconnect to the inner surface of the inner ring of the inertia ring. 6.The propshaft damper of claim 1 wherein the inner surface of the flangehas a press-fit tolerance to securely connect the flange to the outersurface of the second section of the hub.
 7. The propshaft damper ofclaim 1 wherein the hub, the rubber track and the inertia ring are moldbonded together.
 8. The propshaft damper of claim 1 wherein the inertiaring includes at least one sealing lip extending axially around thering.
 9. The propshaft damper of claim 1 wherein the hub includes amounting surface for a fastener.
 10. The propshaft damper of claim 1wherein the apertures include a rubber surface to minimize noise andvibration in case of collision.
 11. The propshaft damper of claim 10wherein the rubber surface of the aperture and the rubber track of therubber track of the inertia ring are molded simultaneously through moldbonding.
 12. The propshaft damper of claim 10 wherein the rubber surfaceof the apertures are installed as a separate snubber.
 13. The propshaftdamper of claim 1 wherein the flange includes a plurality protrusionswhich extend through the apertures of the inertia ring.
 14. Thepropshaft damper of claims 2 and 3 wherein the hub includes a thirdsection to accommodate an inner surface of the flange to align theflange with the other of the transmission flange or the shaft flange.15. A propshaft damper for a vehicle, the propshaft damper comprising:an inertia ring, the inertia ring having an outer ring and an innerring, the inner ring having an inner diameter, an inertia ring having aplurality of apertures, the apertures separated by a plurality ofspokes; a rubber track positioned on the inner diameter of the innerring of the inertia ring, the rubber track having an inner surface, therubber track is located spaced apart from but close to a rotating axisof the damper to provide a high radial stiffness; a damper hub having afirst section, the first section of the hub having an outer surface, theinner surface of the rubber track connected to the outer surface of thefirst section of hub; a fastener connecting the hub to a flange, thefastener extending through the flange and the hub and thus connectingthe hub, the flange and the rubber track of the inertia ring.
 16. Thepropshaft damper of claim 15 wherein an outer surface of a secondsection of the hub connects to an inner surface of the flange to alignthe hub to the flange.
 17. The propshaft damper of claim 15 wherein thefastener is a nut and bolt configuration.
 18. The propshaft damper ofclaim 15 wherein the hub includes a mounting surface for the fastener.19. A method of assembling propshaft damper having a hub, an inertiaring and a flange, the method comprising the steps of: applying a rubbertrack to an inner ring of the inertia ring, the rubber track having aninner surface; applying a rubber surface to a plurality of apertures onthe inertia ring; connecting a first section of the hub to the innersurface of the rubber track; and connecting a second section of the hubto an inner surface of the flange.